Process for reacting gases with liquids



Feb. 27, 1934-. LINDNER 1,949,392

PROCESS FOR REACTING GASES WITH LIQUIDS Original Filed Aug. 22. 1930 INVENTOR [far] H. Zmdne} ATTORNE\LS Patented Feb. .27, 1934 PROCESS FOR REACTING GASES WITH LIQUIDS Karl A. Lindner, Roselle Park, N. J., assignor to American Smelting and Refining Company, New York, N. Y., a corporation of New Jersey Original application An 476,971. Divided and gust 22, 1930, Serial No. this application July 30,

1932. Serial No. 626,601

8 Claims.

This invention relates to metal refining and more particularly to a process for reacting a gaseous reagent with a liquid, such as a molten metal. The present application is a division of my copending application, Serial No. 476,971, filed August 22, 1930.

The invention provides an improved method whereby a gaseous reagent may be reacted with a molten metal to eliminate impurities from the latter. For example, the invention is particularly suited for the removal of impurities, such as zinc, from a molten bath of lead by means of chlorine gas. For this purpose, a cylindrical reaction chamber is provided into which the gaseous chlorine is introduced. A stream of lead is pumped out of the bath of molten metal and is applied to the reaction chamber tangentially whereby it is caused to whirl therein and to come into intimate contact with the chlorine.

The reaction chamber is also provided with a conical base which extends almost to the level of the molten metal. This permits the slag to be washed out of the chamber by means of the molten metal and prevents the apparatus from becoming clogged. Furthermore, the construction permits the apparatus to be started when the lead is at a temperature just above the melting point thereof, inasmuch as danger of lead freezing in the chamber and interrupting the operation of the apparatus is avoided.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended herto, the invention itself, as to its objects and advantages, the mode of its operation and the manner of its organization may be better under.- stood by referring to the following description taken in connection with the accompanying drawing forming a part thereof, in which Fig. 1 is a plan view of a kettle showing the refining apparatus applied thereto; and

Fig. 2 is a side elevation of the apparatus showing the kettle in section and illustrating the relative position of the difierent elements.

Like reference characters denote like parts in the several figures of the drawing.

In the following description and in parts will be identified by specific names for convenience, but they are intended to be as generic in their application to similar parts asthe art will permit.

Referringto the drawing more in detail, the invention is shown as applied to a kettle 10 which is supported by a rim 11 from any' suitable framethe claims work 12 and may be heated in any manner well known in the art.

The refining apparatus comprises a cylindrical reaction chamber 15 which is supported on a pair of beams 16 extending across the kettle and resting on the rim thereof. Said chamber 15 is provided with a gas inlet pipe by means of which the gaseous reagent may be applied thereto and has a conical bottom 19 terminating in a discharge pipe 20 which extends below the surface of the .inlet pipe 22 a pump 24 is provided, preferably of the centrifugal type, having an intake 25 and a discharge pipe 26 which extends from said pump into engagement with pipe 22. Pump 24 is driven H by motor 27 through a reducing gear 28 and a driving shaft 29 which are all mounted on beams 16. Said driving shaft serves to support the pump whereby the entire mechanism including the reaction chamber 15, pump gear 28 may be removed from the kettle as a unit.

In the operation of the above described apparatus in connection with the dezincing of lead, the

,pump may be started when the lead has been 24, motor 27 and heated to a comparatively low temperature, as

for example, 635 F. Since the dischargepipe 20 is immersed in the molten lead and the level of the molten leadpractically reaches the conical base 19, there is but little tendency for the metal within the chamber to freeze when the apparatus is started, even though it is applied to the bath at a temperature not greatly above the melting point thereof.

In reacting lead with chlorine a .considerable amount of heat is evolved and the temperature of the' bath gradually increases, It is accordingly an advantage to start the apparatus at as low a temperature as possible in order to, complete the dezincing operation beforethe bath has reached an excessively high temperature. The opera- .tion should preferably be discontinued when the lead reaches "a temperature of approximately 775 F. inasmuch asabove this temperature the tend- 'ency of thelead to react withthechlorine is increased and the zinc chloride slag tends to be volatilized.

The tangential feed of the lead breaks up the flow of the metal and allows an intimate contact to be made with the chlorinei Furthermore, the

tinuously changing cylinder of metal is thus provided which serves as a lining for the chamber and shields the walls from contact with the reagent. The gaseous reagent within the cylinder contacts with the exposed surface of this metal lining and the products of the reaction, which are lighter than the metal itself, are separated therefrom by the centrifugal action of the moving metal and are caused to segregate toward the center of the chamber, thereby forming essentially an inner cylindrical coating which is drawn downwardly as a continuous core at the bottom of the chamber. This core is withdrawn as such through discharge pipe into the sub-adjacent bath of metal and is permitted to float to the surface of said bath. Due to the fact that slag or reaction products are initially separated and ag-i glomerated in the reaction chamber there is substantially no dispersion of slag particles through the bath of treated metal and a substantially complete separation of the two products is thereby facilitated.

It will be noted that the moving lining of molten metal and slag forms a protective coating over the inner surface of the chamber and thereby prevents the reactive gas from coming into contact with the metal walls and reduces the amount of corrosion which would otherwise take place due to the corrosive properties of the reactive gas. This materlally increases the life of the reaction chamber and decreases the maintenance cost. Furthermore, the products of the reaction are swept out of the chamber, together with the unreacted metal and are prevented from accumulating at the bottom of the chamber and clogging the same or otherwise interfering with the operation of the apparatus.

By pumping the lead at the side and exposing a large. surface to the chlorine it is possible to admit the chlorine at a comparatively rapid rate. For example, in a particular installation using a 100 ton kettle the chlorine was admitted at an average rate of 510 lbs. per hour. During the first two hours when the charge is saturated with zinc a larger quantity is admitted, for example, 600 lbs. per hour, but as the zinc becomes depleted the rate of feed of chlorine is reduced to prevent itfrom escaping through the outlet pipe 20. When the zinc has'been depleted to .02% less zinc chloride begins to form and indicates to the operator that the charge has been completely dezinced. At this point the chlorine is shut off and the lead flow continued until all slag has been washed from the chamber.

scribed as applied to the dezincing of lead by.

the introduction of chlorine and the formation of zinc chloride. However, it is not to be limited to this use, but is suitable for the reaction of The above apparatus has been particularly de-' various gases with a liquid. The above use has been described by way of illustration only.

While certain novel features of the invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. The process of applying a gaseous reagent to a liquid in a reaction chamber, which comprises tangentially introducing the liquid into said chamber thereby causing the liquid to spread out over the walls of said chamber and form a substantially continuous lining thereover whereby the walls of the chamber are shielded from contact with the gaseous reagent and a large surface area of said liquid is presented to said reagent, introducing the gaseous reagent into "said chamber in controlled quantities whereby an appreciable excess of said reagent is avoided,

' and continuously withdrawing the liquid together with the products of'reaction from said chamber.

2. The process ofapplying a gaseous reagent to a liquid in a reaction chamber which comprises introducing the liquid into said chamber in a tangential direction and causing said liquid to follow a substantially spiral path around the walls of said chamber and to spread out over the surface thereof whereby said surface is shielded from contact with the gaseous reagent, introducing said reagent into said chamber in quantities calculated to react with said liquid and utilizing the centrifugal force of said liquid to separate the products of reaction and cause the same to form a core at the bottom of said chamber and removing said core together with the unreacted liquid.

3. The process of treating molten lead with chlorine in a reaction chamber which comprises tangentially introducing the molten lead to said chamber thereby causing said lead to spread out over the inner surface of said chamber and shield the surface from contact with chlorine, introducing chlorine to said chamber in quantities cal"- culated to react with the impurities in said lead whereby an excess of chlorine is avoided, and continuously withdrawing the products of reaetion from said chamber together with the unreacted molten metal.

4. The process of treating molten lead with chlorine in a reaction chamber which comprises applying the molten lead to said chamber and causing the same to spread out over the surface thereof, and to shield the surface from contact with chlorine, introducing chlorine to said chamber in quantities calculated to react with the impurities in said lead whereby an excess of chlorine is avoided, and utilizing the centrifugal force due to movement of the lead over the walls of said chamber for separating the products of reaction and maintaining said products out of contact with the walls of said chamber and continuously withdrawing said products from said chamber together with the unreacted molten metal.

5. The process of reacting a liquid metal with a gaseous reagent which comprises causing said liquid to form a continuously moving, substantially hollow body, reacting the inner surface of the so-formed hollow body with said gaseous reagent, and continuously removing the unreacted liquid and the products of reaction from the lower extremity of said hollow body.

body, reacting the and continuously removing the unreacted liquid and the products of reaction as separate unmixed materials.

8. In refining lead contaminated with zinc, the method which consists of introducing a molten stream of such lead into a cylindrical reaction chamber at a tangent thereby causing the molten lead to substantially cover the walls of said rea 0- tion chamber, introducing chlorine gas into said chamber and withdrawing the reaction products from said chamber.

- KARL A. LINDNER. 

